When did you first notice people were more frequently beginning their answers to questions with the word "so"?

So, two or three years ago, while attending a series of conferences over a few months, I noticed several people doing this. It seemed most of them were young computer programmers, or only out of college a few years. So I guessed this was either a new habit emerging in the academy, or among the technical and scientific community.~

It's not a pet peeve of mine - yet. But I'm curious how this verbal tic got started, how it spread, and what it tells us about the underlying thought processes of the speakers.

This clip is a compilation of excerpts from a recent Charlie Rose interview of David Swensen, head of endowments for Yale University (http://charlierose.com). Of the 19 questions Charlie asked, eight of Swensen's answers began with "So."

I honestly mean no disrespect to Mr. Swensen here. It's just a perfect example of this phenomenon, and I'm really hoping someone can enlighten me on how it got started and what it might mean. I tell you, it's not an easy question to form a Google query for.